[gdal-dev] Projection for OSGB36

[Smart, Gary]

OK - have imported the OSGB36 GEOGCS using the line from the ecw_cs.wkt
file (with first field removed! Oops)

Now I need to transform from OSGB36 to WGS84.  I have set up the
OGRSpatialReference of the input using importFromWkt and the output
using setWellKnownGeogCS("WGS84").  The OGR Transform appears to be
working but the numbers returned are evidently Northings/Eastings
comparable to the numbers in the tfw file.  

 

How can I insist that they come back as Lat/Long?

 

Gary

________________________________

From: gdal-dev-bounces at lists.osgeo.org
[mailto:gdal-dev-bounces at lists.osgeo.org] On Behalf Of Smart, Gary
Sent: 27 January 2010 11:21
To: gdal-dev at lists.osgeo.org
Subject: [gdal-dev] Projection for OSGB36

 

I have a series of OS map TIF files with associated tfw files.  However,
the tif files contain no information about the projection.  I understand
that these files are using OSGB36 AIRY1830

 

Can anyone tell me the precise text specification I need to be able to
set up this projection.  

 

An example tfw file is:

2.5

0

0

-2.5

215000

254000 

 

I tried to importFromWkt with the string from the gdal/data/ecw_cs.wkt
but this did not seem to work.  I don't believe that OSGB36 

 

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